Polymerizing olefin hydrocarbons



N0Y '12,'1940- E. KUENTZEL ETL l'2,221,000'

POLYMERIZING' oLEFIN HYDRocARBoNs Fiied Aug. 11, 1937 uol/Enea WASH rfi/wf] 23 l Prada/cf 'l l A Im/enfors:

Wil/iam L. Webb f yma-fvw U ATTORNEY ronxmrzma omrm'nrnnocmons woran. kunnen Whiting, Ina., and jWilliam l... Webb, Chicago, Ill., assignors to Standad Cil Company, Chicago, Ill., a corporation of In` vApplication August 11, 1937. serial No. 158,454

v claims. (ci. zoo- 94) UNITED? STATES. PATENT-OFFICE i This invention relates to thel manufacture of l. resins by the polymerization of isobutylene and particularly the polymerization'of liquid iso-5 butylene in the presence of catalysts. Mixtures of isobutylene, particularly mixtures of isobutylene with normal butylenes and butane may be employed and we prefer to employ the liquefied gaseous by-product of cracking petroleum oils known as light absorptionnaphtha, containing about to `25% of isobutylene, the remainder being mostly normal butylenes and butanes.

One of the objects of our invention is to convert isobutylene to higher molecular weight hydrocarbon resins by catalytic polymerization under extreme prsurlhereby resins of higher molecular-'weight are produced than heretofore. Another object of our inventiondis to produce desirable high molecular `weight isobutylene resins without theuse of costly, extremely low` temperature refrigeration heretofore required.

Other objects of the invention will be apparent v from the following description.

The accompanying drawing which forms a part of this specification describes one means of carrying out the process. Referring to the drawing, I0 is a supply4 tank for liquefied isobutylene gas, for example, isobutylene diluted with other `hydrocarbons such as liquid propane, butano or naphtha. or a supply of light absorption naphtha obtained directly from the fractionation of liqueed cracking still gases.

The vliquefied isobutylene is conducted by line Il to pump I2 byv means of which it is subjected to extremely high pressure usually above 5,000 pounds 'per` square inch, and we prefer to employ pressures between 10,000 and 50,000 pounds perl square inch. Still higher pressures, for example 100,000 pounds per square inch may be employed.

In general, it is essential to. use a pressure atleast i0v 1000 pounds per square inch above the vapor pressure of the hydrocarbon at the temperature cf polymerization, to obtain the desired advantages of our process.

The hydrocarbon stream under the desired high 145 pressure is conducted by line I3 to reaction vessel I4 which is preferably constructed of forged steel of relatively small diameter towithstand the high pressure employed. The reaction vessel I4 is provided with internal cooling coils I5 to absorb the heat of polymerization of the olen. Cooling water, cold brine, liquid propane.v

liquid ,ammonia on other suitable refrigerant may be supplied to coil I5 by connection I6 and discharged by connection I1. Catalyst may be introduced by either or both valved lines I0. It

is preferred to employ boron fluoride. (Bib) as a. catalyst which may be maintained as a liquid in supply tank I9 whence it is withdrawn by line 20 and pump 2l, forcing it under high pressure into the reaction vessel I4 at the desired rate. i The amount of catalyst required will usually be about 0.5% to 5% by weight 4of the olelln treated. The boron fluoride may also be dissolved in an inert hydrocarbon solvent such as hexane to facilitate controlling th introduction thereof. 3 The reaction temperature in reaction chamber i4 is controlled withinthe desired limits and is preferably maintained at about room temperature by the use of cooling water in coils I5.,- although temperatures as high as 100 c. may be ll used. v The polymerized reaction product containing excess catalyst is withdrawn by line 22, pressure. reducing valve 2l and is discharged into evaporator 2l equipped with heating coil 25. Unpolywhere the remaining catalyst is removed and 25 neutralized, the product being discharged by line 29. In order to facilitate handling, a diluent may be introduced by valved line 30,'suitable diluents being naphtha, benzene, carbon tetrachloride, light lubricating oil. etc. 'J 'Ihe diluent 80 may be subsequently removed by distillation or allowed to remain in the product where the use of the product permits. g

By employing our` high pressure polymerization process, for example operating 'at a pressure of $5 20,000 pounds per square inch, it is possible to obtain a Tconsiderable increase in the viscosity and molecular weight of the polymerized product. Thus, by operating at ordinary pressures and room temperature,isobutylene may yield a prod- 40 v uct having an average .molecular weight of about l understood whetherthis eilect is the result of more frequent molecular collision or whether the extremely high pressure produces a more active catalyst `complex. It is believed that the true catalyst in reactions of this type is a complex organic-inorganic compound formed between the hydrocarbon and the active metal halide and it containing isobutylene into by` the extremely polymerizing hydrocarbons resins in the presence of a catalyst, the improvements which comprise subjecting the hydrocarbons above 5,000 pounds per square inch, contacting the said hydrocarbons-while under said pressure and at a temperature perature and 100 C., with a boron uorlde catalyst to form high molecular weight resins, reducing the pressure and thereafter separating the saidreslns and the reaction mixture.

2. The'process of claim lfwherein the pressure employed is between about 10,000 pounds per sqire inch and about 100,000 pounds per square n 3. In the process of converting liquid isobutylene into high molecular weight polymer resins, the improvements which comprise polymerizirig the isobutylene inthe presence of a boron iiuoride `'2,221,000 is possible um the composition of this true om.

. 4. The process oifclaim 3 to a pressureA between about room terncatalyst while under a pressure between about 5,000 pounds per square inch and about 100,000 pounds per square inch and a temperature between about room temperature and 100 C., reducing the pressure on the reaction mixture and thereafter separating the said polymer'resins fromany unpolymerized hydrocarbon gases and excess boron fluoride. wherein the liquid isobutylene is present as mixture of hydrocarbons.

5. The process of claim 3 wherein the liquid isobutylene is present as part of a light absorption'naphtha. l

' 6. 'I fhe process o! claim 3 wherein the temperature is approximately room temperature.

'1. The process oi polymerizing `isobutvlene which .comprises subjecting the isobutylene to a. pressure of about 20,000 pounds per square inch, contacting the said isobutylene, while under said pressure, with borontriuoride, while maintaining the reaction at about room temperature thereby forming high molecular weight polymer resins.. thereafter reducing the pressure and part of a recovering the said polymer resins. v A n W ARD E. KUENTZEL. wnLIAMvL. WEBB. 

